The state of the art in setting type provides phototypesetters capable of producing high resolution characters at high speed, for example at speeds up to 8,000 characters per second. The media upon which this typesetting is produced is photographic film or paper intermittently fed from a roll supply of a width to accommodate line lengths up to 100 picas, a media width of nominally four to eighteen inches. The media has a photo sensitive emulsion that is exposed to a cathode ray tube and lens system at a typesetting window where the photocomposition is resolved; there being phototypesetters which produce media with the emulsion side up, and those with the emulsion side down at the output. The exposed media is advanced or retracted at a maximum throughput rate of to six to seven inches per second, and there is an automatic cutter that is electrically responsive to cut the media into varied length sheets as required as it issues from this phototypesetter.
Associated with the above phototypesetter, the state of the art provides media processors that have a throughput rate up to three inches per second, limited to this rate by the dryer function thereof. That is, at this speed the processor is limited by the dryer, and might not sufficiently dry all media at all relative humidity conditions. Therefore, a 2.4 in./sec. throughput rate is more practical and is relied upon. The processor under consideration receives the exposed media emulsion side up only and passes the same through sequentially separate developer, fixer and wash tanks, followed by the aforementioned dryer and deposited into a receiving bin. The developed media is then ready for make-up into page form preparatory to producing the plate used in the actual printing.
A characteristic of newsprint and the like is that the typesetting is organized into columns. For example, a newspaper will be comprised of six columns separated into different news articles between the top and bottom of a page. Accordingly, page composition requires the starting and stopping of the typesetting, for the arrangement of news articles in sequence and in side by side relation, including spaces for pictures and the like. Separation is referred to as "leading" when progressing downwardly, and in the art of phototypesetting "reverse leading" is practiced by reversing the film media and setting other columns of type adjacent to previously set columns of type. Since the throughput rate of the phototypesetter is approximately twice that of the film processor, it is feasible to reverse the phototypesetter a number of times while the processor continues to operate at its full capacity. Therefore, it is an object of this invention to provide a buffer storage of film media in the transporter, for film media in either an emulsion "up" or emulsion "down" disposition.
It is a general object of this invention to provide a transporter to handle the media, whether film or paper, in a manner to eliminate scratches and static, by using rollers and reducing sliding contact to a bare minimum. It is also an object to handle cut lengths of media, ranging in length from a twelve inch minimum to a fifty inch maximum, allowing a leader up to seventeen inches and a trailer up to seven inches on each end of a typeset page of twenty four inches. It is significant therefore that the aforesaid automatic cutter of the phototypesetter preceeds the operations performed by the transporter, also that the input into the processor supersedes the operations performed by the transporter. Accordingly, it is an object of this invention to coordinate the maximum throughput rate of the phototypesetter of 6 and 7 in./sec. with that of the processor of 2.4-3 in./sec., the transporter being characterized by storage means and control means therefor. In practice, the transporter will function at 12 in./sec., the faster rate providing for a continuous flow of media through the processor when providing a buffering function. Although the throughput rate of end product is limited by the processor, the buffer storage provided in the transporter permits repeated "reverse leading" so that the average rate is that of the processor.
With the first form of transporter disclosed herein, the media is delivered by the phototypesetter emulsion side up as required for the functions of processing. The media is automatically cut into sheet form limited to maximum length by the transporter when it reaches the final set of transporter rollers, or the media may be fed out in shorter lengths as required. As soon as the sheet media is cut from the media issuring from the phototypesetter it accelerates to the 12 in./sec. throughput rate of the transporter. A feature is slip clutch means that permits continuous operation of the transporter rollers at a maximum throughput rate, allowing advancement of the media at the throughput rate of the phototypesetter, allowing retraction of the media into the phototypesetter, allowing said maximum throughput rate of cut media when severed from the phototypesetter, and also preventing bunching of the media against the slower throughput rate of the processor. The media passes through a turn gate where it operates a detector switch before reaching the processor. There is a time delay which ensures positive entry into processor engagement, whereupon the turn gate drops so as to direct the oncoming media, as the case may be, into a buffer storage area thereby accommodating the greater transporter rate of delivery and so that the entire fifty inch of transport length can be occupied by the following length of media during typesetting, protected by the function of the detector switch which inhibits operation of said automatic cutter until the tail of the existing sheet of media releases said switch.
With the second form of transporter disclosed herein the media is delivered by the phototypesetter emulsion side down and therefor requires reversal to an emulsion side up condition as required for the functions of the processor. The media is automatically cut into sheet form of maximum length by the phototypesetter when it reaches the final set of transporter rollers, and it may be fed out to shorter lengths as will be described. As soon as the sheet media is cut from the media issuing from the phototypesetter, it accelerates to the 12 in./sec. rate of the transporter. A feature is slip clutch means that permits optimum operation of the transporter rollers at a maximum throughput rate, allowing advancement of the media at the throughput rate of the phototypesetter, allowing retraction of the media into the phototypesetter, and allowing said maximum throughput rate of cut media when severed from the phototypesetter. A first detector switch senses the presence of media passing through the final set of transporter rollers and activates a motor so that the film media enters the turn gate to be driven by a pair of rollers of the gate and caused to enter into a buffer storage area in an emulsion "down" condition. When the trailer of the cut media releases said first detector switch and after a short time delay the turn gate motor is quickly stopped by means of a brake with the media trailer still engaged between said drive rollers thereof, while said turn gate is rotated to align with the input rollers of the processor. Alignment of the turn gate with the processor input rollers is sensed by a second detector switch to activate the motor forwardly driving the pair of turn gate drive rollers to pull the media from the buffer storage area in an emulsion "up" condition. A third detector switch senses the media entering the processor and by means of a time delay ensures actuation of the turn gate drive rollers until there is positive engagement of the media with the input rollers of the processor. At this point the turn gate motor is stopped and a slip cluth means permits the processor to pull the film media out of the buffer storage area. When the trailer releases said third detector switch, the turn gate and drive rollers return to a buffer mode, and a phototypesetter "wait" mode is released to enable cutting of the next sheet of exposed media.